Improvement in apparatus for grinding and shaping



, J. W.. HYATT.

'Apparatus for Grinding and Shaping Slent.

No. 204,151. Patented May 28,1878.

l ooooo oooo 0900.00 vOOO-O WiTNEssEs mvENToR ATTORNEY I MPETERS, PHOTOLITHDGRAPHER.v WSHINGTON. D. C.

JoHN w. HYATT, or' NEWARK, NEW JERSEY.

' IMPRovtM'ENT IN' APPARATUS FpoRiGRlNmNG AND SHAP'INGSLATE. .Y

Specication formingfpart of Letters Patent No. 2,041,151, dated May28,1878; application filed i September 20, 187?. Y

To all 'whom 'it 'may concern: Be it known that I, JOHN W. HYATT, ofNewark, in the county of Essexand State of New Jersey, have inventedcertain new and useful ,Improvements in a Method of and Apparatus yforGrinding and 'Shaping Slate, of which impl ovements the following is aspecification, reference being had tothe accompanying drawings, formingpart of this specifi.- cation, in which- A v Figure 1 is a longitudinalcentral section through the apparatus; Fig. 2, a transverse sectionthrough the apparatus at the line a: a; of Fig. 1; Fig. 3,' a plan ofthe apparatus' with the lhood and its'appendages removed, thegrinding-rolls shown in these threeiigures having plain surfaces adaptedvto 'grind-ing only; Fig. 4, a plan showing my improved grooved rollersfor shaping as well asv grindf ing; Fig.'.5, a plan view of thereceivingLb'oX, and Fig. 6a plan of an improved roll-surfacingdevice.-I. 1 It isthe objectY ofy my invention to Asubdivide slabs of slate 'andshapethe piecesinto slate-,pencil blanks, and also `to grind slateswhichlare to be framed to a'uuiformthickness and'smooth surface.- v v pY Tothese ends 'my invention, consists .in an improved apparatus 'inwhich, for grind.- ing and shaping pencil-blanks, the slab of slate isfed vbetween small feed-rolls and guide-'plates mi two grimlin'g` andshaping rolls, .so as to present a continuous Aseries of ygrinding-edgesand grindingand shaping depresfy sions, -the edges subdividing 'the'slab intov pieceslongitudinally 'and the grooves shaping the piecesinto' pencil-blanks, as ,will presently be described. For grindingandsu'rfa'cling slates the apparatus is the same, ecept that Isubstitutefor'the grooved Vrolls rolls having' plain surfaces. In allcaseshowever,

the rolls,- whether plain orgrooved, have their entire surfacescoated'with'a preparation of l 'emery orother grinding material orcompound, such preparation or .compound having the properties requisite''for use in water.

As I propose to grindand surface the slate's in water, and as, theg'rnding-'siirface'of the rolls wears'rapidly in places under thisoperation, it isa further object of Amy improvement to thesurfaces Vofwhich are `grol6ved provide means for restoring-to the rolls therequisite true and even surface whenever' such wearingoccurs, andwithout stopping `the rolls to dress them; and to this end myoinvenltion consists in combining Withithe plainfsur-j faced rolls, a pair oftruin'g-rolls made to bear upon the surface of the grinding-rolls, soasto vproduce the desired effect. ,Forajmore positive action in thisrespect, I also propose using, instead of the truing-rolls, a carbonpoint or the end of a bar of` hardened steel, adjustable orself-adjusting', and traversing along the surface of the grinding-rolls,so as to restore their surface when it becomes unil even. Thesetruing'rollsor truing-points 'are applicable to the plain grinding' andsurfacing rolls, but not to the groo've'd grindingy and shaping rolls..i ii In'the operation of my apparatus, theA slate fed tothe rolls passesfromthem down iii/toa receptacle havin g aperforatedbottom, is placedbeneath the rolls in' a waterftrcugh', and which fis 'supported in thetrough on ways, along which it can be' slid in orout asdesired. .Theltrough is ill'e'dkwith `water, sof'that the Vgrifnding-r'olls constantlydip therein.

' y vThe trough A is a water-tight box', open'at top,.at one end ofwhich the feeding, truing, and grinding mechanisnlis mounted andsupiported in a hood, B, which is secured to' the top of the 'trough Aby `hingesor screws, so 'as to be readily opened or removed.. *'Af're-"ceivingfbox, C, open 'at ,top and havin'gap'erforated bottomis, fittedto ,slidejalong `the waysj b, secured upon the' inner sidesjof thetrough and nearthe"bottomk there'.,k The troughis filled with Water, sothat thegrind ing-rolls will constantlydip therein. The grinding-rolls'DD', properlyjeoated, as already mentioned, are mounted in bearingssecured to the side pieces, of the trough,1and at least one of the rollshas a range of move'- ment in its bearings longitudinally to thetrough', so that it maybe adjusted toward or from' the other' roll, asmay be' required, for

grinding thinner or thickerjslateyand it will l be observed, as showninl Ithe drawings,- that the bearings of the grinding'o'r grinding andshaping rolls are at the `proper height above the -trouh to permitthel'o'we'r partofthefrolls tO bie immersedin Vthe Water, in the trough.A

when the trough is lled. These rolls are rotated toward each other bymeans of belts and pulleys or gearing.

The hood or cover B extends over and iucloses the grinding-rolls,affording bearing for the feed-rolls and the trning-rolls ortruingpoints, as will presentlybe more fully described. This hood alsoprevents the splashing of water from the grinding-rolls, which wouldotherwise occasion inconvenience to the operator.

Across the center of the hood B a slot is cut, coinciding with the spacebetween the grinding-rolls, and having such length and width as to admitof the passage of such slabs of slate as are to be operated upon by theapparatus. In this slot two guide-plates, .E E, are properly secured,depending from the hood directly over the space between thegrindingrolls. Above the slot, and coinciding with the guide-plates, aremounted a pair of small feedrolls, F F, which should have such adjustability toward and from eachother as may be necessary in feedingdifferent thicknesses of slate. These feed-rolls are made of or coveredwith vulcanized rubber, as in wringing-machines, so as to bear upon theslate being fed between them. The feed-rolls are also driven by pulleysor gearing and rotate toward each other. vIn order to maintain auniformly plain surface upon the grinding-rolls,I mount in the hoodapair of metal truing-rolls, G G, each of which bears upon the surface ofone of the grindingrolls at a point slightlyI below its verticalcenter-line,- and acts as an evener upon the surface of thegrinding-roll, restoring such surface where it is ridged or worn in thegrindingoperation. These truing-rolls are respectively adjustable towardor from the grindingrolls, so as to regulate their bearing upon thegrinding-surfaces, asdesired, and they are rotated by pulleys and belts.or gearing at a slow speed, each in a direction contrary to that of therotation of the grinding-roll upon which it bears. Where the wear is toorapid or too great to be restored by these truing-rolls, I use for thepurpose of restoring the surface of the grinding-rolls a carbon point orthe end of a bar of hardened steel for each grinding-roll. Thesetruing-points are mounted in holders h, Fig. 6, traveling in guides fi,supported upon the hood in bearings k, and having screws and rubbersprings for regulating the bearing of the carbon points upon the surfaceof the grinding-rolls. The movement of the truingpoint along the surfaceof the roll may be effected by hand, or by any of the well-known devicesfor giving a reciprocating traverse to a holder along the guides. I havespecified the carbon point or the hardened steel as the best means knownto me for obtaining the positive action mentioned; but I contemplateusing any other equivalent in lieu of the truing-rolls. As alreadymentioned, these truing-rolls or truing-points cannot be used with thegrooved grinding and shaping rolls.

The grooved grinding and shaping rolls H H, Fig. 4, are mounted androtated as already described, and can be substituted for theplain-surfaced grinding-rolls when it is desired to form slate-pencilblanks. Their surfaces are coated with a similar preparation or compoundof emery or other grinding material, such preparation or compound havingthe properties requisite for its use in water.

The grooves in each roll are of semicircular sectioncorresponding innumber, depth, width, and relative position with those in the other, andthe plain grindingsurfaces between the grooves in each roll are of suchwidth as will insure the best abrading action upon the slate Withoutspalling it off at the edges of the divisions.

The operation of my improved apparatus is as follows: For grinding `andshaping slatepencil blanks, the slabs of slate are, as usual, preparedof uniform size, and, as near as may be, of uniform thickness. Thegrooved rolls H H, Fig. 4, are substituted for the rolls D D', Fig. 1,the truing-rolls G G or truin g-poi nts being moved up in theirbearings, so that they will not touch the surface of the grooved rolls.The box G is placed in the trough and slid along the ways b until it isbeneath the grooved rolls, as in Fig. 1. rIhe trough A is filled withwater up to such a height that the under side of the rolls HH will beconstantly immersed.

The machine being started, a slab of slate is inserted between'thefeed-rolls F F,and passes down between the guide-plates E E until it is`taken between the rollsH H, which have been adjusted at the properdistance from each other to insure the desired action, and which rapidlyabrade the slab at those points immediately acted upon by the surfacesbetween the grooves, and, secondarily, by the surfaces of the grooves,until the slab is subdivided into longitudinal pieces, each of which isa slate-pencil blank, with a slight iin upon each side, these blanksgradually passing down between the rolls until finished, when they dropinto the receiving-box C. To convert these blanks into slate-pen cils,the fins are removed in any suitable manner, by hand or by tumbling.

To grind and smooth without subdividing slabs of slate, the plain rollsD D are substituted for the grooved `rolls H H, and these rolls D D'reduce the surface of the slab on both sides toa uniform plane andsmoothness, this uniformity extending from `edge to edge and from sideto side, which, so far as I know, has not been the case with anyapparatus prior to my invention. The slab is fed to and delivered fromthese rolls as already described, except that it is delivered in onepiece instead of in pencil-blanks. y

When the plain-surfaced rolls D Dl are substituted for the grooved rollsH H, the truin grolls G G or the truing-points aremoved down in theirbearings, so as to bring them in contact with the surfaces of thegrinding-rolls, as hereinbefore explained.

I have found in practice that both the plainsurfaced and the groovedrolls act more effectively by the abovedescribed mode of grinding inwater, and this I believe has not been heretofore done in any machine ofthis class; nor ain I aware that any slate-grinding apparatus prior tomy invention could form pencil-blanks from a slab of slate, as abovedescribed, bypassing the slab between a pairof grinding-rolls revolvingin opposite directions and acting simultaneously on opposite sides ofthe slab, so as to form pencil-blanks by a single passage of the slabbetween the rolls, in contradistinction to the only previous way knownto me of cutting first one side of the slab and then the other by twosets of cutters acting successively against a slab supported on astationary bed.

What I claim as new, and desire to secure by Letters Patent, is-

l. The method hereinbeicre described of grinding and shaping a slab ofslate into pencil-blanks bypassing the slab between grooved grinding andshaping rolls, which act simultaneously on opposite sides of the slab tocut the slab into blanks while single set of rolls.

2. The combination, in a slate-grinding inachine, of the trough and thereceiving-box with the grinding and shaping or grinding rolls,substantially as and for the purposes set forth.

3. The combination', with the trough and the grinding and shaping orgrinding rolls, of a hood, substantially as and for the purposes setforth.

4. The combination of the feedvrolls, thel guide-plates, and thegrinding and shaping or the grinding rolls, substantially as and for'the purposes set forth.

5. The combination, with the grinding-rolls, of truing rolls or points,substantially as and for the purpose set forth.

J. W. HYATT.

Witnesses GEO. H. SMALLEY, J. E. HOWELL.

passing between a

